Take some time throughout your day to give your body a nice stretch. Extend your arms up to the sky or towards the ceiling. Reach down and toes your toes. Angle your neck to one side, then the other. Feel your muscles relax and your mind calm a bit as you do.
In addition, consider taking a yoga class. The benefits of starting your own practice not only include stress-relief, but improved flexibility and muscle tone, and an overall sense of well-being.